Capsule, system and method for the preparation of a beverage and a method for manufacturing such a capsule

ABSTRACT

A capsule for preparing a predetermined quantity of beverage comprises a circumferential first wall, a second wall closing the circumferential first wall at a first end, a perforate and/or porous third wall closing the circumferential first wall at a second, open, end opposite the second wall arranged for draining the prepared beverage from the capsule. The first, second and third wall enclose an inner space comprising an extractable product. The extractable product in the inner space has particles falling within a preselected distribution by weight. A 10th percentile of the particle size is 20-60 μm, a 50th percentile of the particle size is 400-600 μm and a 90th percentile of the particle size is 700-1000 μm.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of International PatentApplication No. PCT/NL2009/050839 filed on Dec. 30, 2009; which claimedpriority to European Application Nos. EP09162941.0 filed on Jun. 17,2009, EP09162917.0 filed on Jun. 17, 2009, EP09162927.9 filed on Jun.17, 2009, and EP09162984.0 filed on Jun. 17, 2009—all of which arehereby incorporated herein by reference.

BACKGROUND

The invention relates to a capsule for preparing a predeterminedquantity of beverage suitable for consumption using an extractable or asoluble product, for instance roast and ground coffee, comprising acircumferential first wall, a second wall closing the circumferentialfirst wall at a first end, a perforate and/or porous third wall closingthe circumferential first wall at a second, open, end opposite thesecond wall arranged for draining the prepared beverage from thecapsule, wherein the first, second and third wall enclose an inner spacecomprising the extractable product.

Such capsules are known per se and can be used in an apparatus forpreparing a beverage. They provide convenience in use as well asreproducible extraction conditions, resulting in easy preparation of acup of coffee with a constant quality. The known capsule can be an opencapsule, comprising a circumferential wall and an exit area adapted fordraining prepared beverage from the capsule. In the inner space of thecapsule, an amount of extractable product, such as roast and groundcoffee is provided, for instance by providing an amount of coffee with asmaller volume than the volume of the inner space. Such a capsule can beused in a beverage production apparatus in which a liquid under pressureenters the capsule in order to interact with the extractable product inthe capsule and to drain the beverage from the capsule out of theapparatus into a container, such as a coffee cup.

When using the known capsule with an open exit area and loosely providedroast and ground coffee, water supplied to the capsule may rush throughthe capsule resulting in a less than desired pressure build-up insidethe capsule, thereby extracting the coffee with a relatively lowextraction pressure. This may result in an uncontrolled beveragepreparation process which may adversely affect the prepared beverage.Especially, the quality of the coffee may be inferior, for instancebecause due to a lower extraction pressure, the coffee may be watery oran inferior foam layer due to a lower CO2 content of the coffee beveragethat occurs when extracting at lower extraction pressure, while CO2 isimportant for creating foam.

SUMMARY

It is an object of the invention to provide an improved capsule providedwith an extractable or soluble product for the preparation of a beverageand more specifically to at least diminish the above problem. Inparticular, it is an object of the invention to provide an improvedcapsule comprising roast and ground coffee which results in improvedtaste of coffee prepared using such capsule.

Thereto, according to a first aspect of the invention, a capsule of theabove described type is provided, wherein the extractable product in theinner space of the capsule has particles falling within a preselectedrange of distribution by weight, wherein a 10th percentile of theparticle size is 20-60 μm, preferably smaller than 40 μm, wherein a 50thpercentile of the particle size is 400-600 μm, preferably 450-550 μm andwherein a 90th percentile of the particle size is 700-1000 μm,preferably 825-950 μm.

Preferably, the capsule is provided with openings in an exit areathereof, which may be substantially equally distributed about across-section of the exit area. It will be appreciated that a flange ofthe capsule may not be regarded as a suitable exit area.

It is found that when such capsule is being used for preparing coffee,the particles having smaller sizes in the given distribution by weightsubstantially do not dwell inside these openings thereby improvingcoffee preparation process due to improved flow patterns. In addition,it is found that an amount of undesirable sediment in a cup decreaseswhen a capsule provided with exit openings is used with respect to acapsule which is intended to be torn during use. In particular, it isfound that in an open capsule according to an aspect of the inventionprovided with openings in the exit area particles may be sized formatching these openings thereby improving flow patterns of a liquidexiting the capsule. In addition, it is found that such matching maylead to an improved oil concentration in the resulting beverage as wellas to an improved Dry Matter Accumulation (DMA) while preserving thesetting time substantially the same as in the capsule known from theprior art. More in particular, such a particle size distribution of theroast and ground coffee inside the capsule prevents collapsing of thecoffee bed upon pressurizing the coffee with water.

Advantageously the coffee is compacted inside the capsule. For example,a suitable coffee starting material may be compressed inside thecapsule.

It will be appreciated that particles of the coffee starting materialentering the capsule (thus not yet compacted) may have somewhat smallerdimensions than the particles of the end product set forth in claim 1.

For example, particles of the coffee starting material may have thefollowing distribution by weight: a 10th percentile of the particle sizemay be 25-55 μm, preferably less than 40 μm, a 50th percentile of theparticle size may be 450-550 μm and a 90th percentile of the particlesize may be 600-800 μm.

It is understood that due to the step of compacting, for example bycompressing the coffee starting material, the particle size may increasedue to particles sticking together.

In the capsule, as a result, due to the compression of the coffee, therelatively small particles may be enclosed by the relatively largeparticles such that the relatively small particles can not displacetowards the exit filter before the preparation of the beverage. Whensupplying water to the inner space of the capsule, the relatively smallparticles may flow with the water towards the exit filter to form theflow restriction together with said exit filter. At the same time suchparticle size distribution provides a high quality coffee with a goodtaste. If the overall particle size is too small, the coffee bed maycollapse such that prepared beverage can not easily pass throughresulting in an undesired high beverage preparation time. If, on theother hand, the overall particle size is too large, the supplied fluidwill rush through the coffee, resulting in watery coffee beveragecomprising a low concentration of dissolved dry matter without having afoam layer.

It is noted that the above mentioned preferential particle sizedistribution according to the invention is determined by means of acommonly known Sympatec analyzer that is suitable for determiningparticle distribution and size in dry products. Such an analyzer may bea Sympatec Central Unit “Helos” used in combination with a drydispersion system Rodos T4.1 unit. The used measuring range R7 comprises0.5/18.0-3500 μm. A sample is positioned in the measuring unit. By meansof laser diffraction technology, the particle size distribution of saidsample is determined. The light emitted by the laser is diffracted bythe sample particles. The amount of diffraction is dependent on theparticle size of the roast and ground coffee of the sample. The diffusedlight is detected by a detector after passing a lens, said lens being aR7 lens.

It will be appreciated that coffee may be suitably compacted prior tobeing inserted into the capsule and/or within the capsule. Compactingprior to introduction into the capsule may be achieved using a suitableplunger. It will be appreciated that this operation may be preceded by astep of densification wherein a flow of the extractable product ispushed through a narrow diaphragm under pressure. Compacting in thecapsule may be achieved by suitably compressing the coffee startingmaterial in the capsule. By compressing the coffee starting material inthe capsule, particles of the roast and ground coffee are pressedagainst the walls of the inner space of the exchangeable capsule,thereby preventing occurrence of preferential fluid flow paths along therespective walls of the capsule. This also may be advantageous in casethe capsule has to be placed in an apparatus such that the exit filteris directed sideways, e.g extending in a substantially vertical plane.By providing a capsule with compacted coffee inside, also in a rotatedposition of the capsule, the coffee stays located next to the entireexit filter, thereby preventing preferential fluid flow paths.Consequently, the supplied fluid, such as water, is directed from theentrance area through the coffee bed to the exit area of the capsuleindependent of the position of the capsule, providing a controlledbeverage preparation. Thus, by compressing the coffee, the speed of thefluid flow can be controlled between the entrance area and the exit areaof the exchangeable capsule. Furthermore, such a compressed coffee bedtogether with the exit area of the coffee provides a desired flowrestriction within the capsule during preparation of the beverage. Thisallows a higher extraction pressure building up within the inner spaceof the capsule, thereby providing a higher extraction pressure to buildup in the capsule. For instance, such that a coffee beverage with adesired strength and with a higher CO2 content resulting in a highquality coffee beverage with a foam layer may be provided.

Preferably, the capsule according to the invention comprises an amountof coffee suitable for preparing a single portion of beverage,preferably a single cup of the beverage, e.g. from 30-200 ml of theprepared beverage. The capsule may therefore comprise 4.0-8 grams,preferably 4.9-5.7 grams, preferably approximately 5.3±0.2 grams ofroast and ground coffee. For instance, a capsule comprisingapproximately 5.3 grams may be used for preparing a cup of espressocoffee. The exchangeable capsule, thus, is a single-portion-pack. Hence,the capsule is suited for preparing a predetermined amount of coffee bysupplying a predetermined amount of hot water under high pressure to thecapsule. A capsule comprising the mentioned amount of coffee provides acoffee beverage with a favorable amount of foam, a desired amount ofsoluble dry matter extracted from the coffee starting material. It isnoted that a favorable amount of foam preferably is at least about 5 mlof foam, or more, for instance 9 ml of foam, on top of a preparedbeverage comprising about 40 ml. Furthermore, the capsule comprises adistribution of the particles loose enough to prevent formation of aflow restriction in the entire coffee bed preventing an undesired longpreparation time of the beverage and a large amount of coffee oilcomprised in the beverage.

In further elaboration of the invention, the inner space of the capsulepreferably has a volume of approximately 10-14 ml, preferably 11.5-12.5ml, more preferably approximately 11.8 ml.

It is advantageous if the entire inner space is occupied by theextractable product, for instance the roast and ground coffee. Hence,optimum use may be made of the internal volume of the capsule whenmatching densities of the ground coffee are used. This further providesthe advantage that the extractable product cannot be displaced entirelyinside the inner space when the fluid flows through the capsule, so thatno preferential paths can be formed. Furthermore, because the entireinner space is occupied with the coffee, no water will remain inside thecapsule between the coffee and the respective side walls after preparingthe beverage. Therefore, the capsule can be removed from the apparatuswith a minimum risk of soiling the apparatus because of water leakingfrom the capsule.

It has been found by the applicant, that it is advantageous according toa further elaboration of the invention, if the roast and ground coffeeis compressed such that the compressed coffee in the inner space of thecapsule comprises a substantially homogenous density. During use, theparticles of such homogenous coffee inside the capsule may beredistributed resulting in a relatively loose coffee bed layer adjacentthe second wall, thus the entrance area of the capsule and a relativelycompact coffee bed layer adjacent the third wall, thus the exit area ofthe capsule. Such compact coffee bed layer together with the exit filterprovides a filtering capacity of the capsule with a desired pressuredrop. Thus, the compact coffee bed layer and the exit filter togetherprovide retarding of the outflow of the prepared coffee beverage fromthe capsule.

According to another aspect of the invention, the third wall comprisesan exit filter for draining prepared beverage from the capsule, whereinthe exit filter for instance is formed by a porous or perforate sheet.The exit filter may be formed by a woven or non-woven fibrous sheet,such as filtering paper, or a film, such as a polymeric film, providedwith a plurality of exit openings. In use such an exit filter togetherwith a compact coffee bed layer adjacent the filter provides a desiredflow restriction that may result in a coffee beverage with a goodquality and good taste. By using filtering paper as the exit filter alow-cost third wall is provided. Furthermore, the third wall being offiltering paper may result in filtering oil from the beverage, i.e. fromthe coffee, before supplying the coffee to the container, such as thecup. This may be advantageous to reduce the amount of oils in the coffeewhich may adversely affect the taste and/or quality of the coffee. It isespecially advantageous to filter cafestol from the coffee. Moreover,the third wall being porous may provide the advantage that the beveragecan be drained from the capsule over substantially the entire crosssection of the inner space. Hence, the beverage can flow out the innerspace very homogeneously. This may prevent the existence of preferentialfluid flow paths inside the inner space. Preferential fluid flow pathsare known to reduce reproducibility of the process of preparing thebeverage.

It is advantageous if the exit filter, for instance of the polymericfilm, comprises 80-140 exit openings, wherein an opening diameter isbetween 0.20 mm±0.05 mm and 0.40 mm±0.05 mm, preferably approximately0.3 mm±0.05 mm. Such exit openings together with the relatively smallcoffee particles that are redistributed during water supply and locatedadjacent the openings may provide the desired flow restriction and thuspressure drop. Due to said openings, the prepared beverage will leavethe capsule with a desired speed such that the preparation time will notbe too long, for instance no more than 40 seconds, preferably no morethan 30 seconds. Furthermore, the openings are small enough to preventcoffee particles from leaving the capsule and ending up in the cup withprepared coffee beverage. The preferred amount of openings in the exitfilter enables the exit filter together with the compact coffee bedlayer adjacent the filter to form a desired flow restriction such that acoffee beverage with an acceptable oil balance, a desired brewingstrength and an acceptable preparation time is obtained. Such a coffeebeverage will have a good quality and good taste.

In further elaboration, the first circumferential wall is substantiallyrigid. In general, the circumferential first wall may have any shapesuch as cylindrical, hemispherical, frustoconical or polygonal, such ashexagonal or octagonal.

Preferably, the capsule comprises an entrance filter, wherein theentrance filter has a flow resistance that is lower than the flowresistance of the compacted extractable product in combination with theexit filter, avoiding excessive pressure build-up upstream of theentrance filter. This is favorable since such upstream pressure build-updoes not contribute to the brewing of the beverage.

According to a further aspect of the invention, the extractable productis compacted into a tablet from the coffee starting material. Thisprovides the advantage that the risk of preferential fluid flow pathsoccurring in the compacted extractable product tablet is reduced. Itwill be appreciated that when using the compacted tablet, the secondwall may be omitted from the capsule, as the risk of spillingextractable product is greatly reduced.

In further elaboration of the invention, the tablet may comprise atleast one bore extending from the side of the tablet facing the secondwall in the direction of the third wall. The bore thus provides aninfusion means for wetting the tablet in a homogeneous manner.

It is also possible that the extractable product is compacted into aplurality of tablets, preferably of mutually different packing density.It is for instance possible that the extractable product is provided asa single stack of tablets having mutually different degrees ofcompacting. It is for instance possible that the degree of compactingincreases per tablet in the direction from the second wall to the thirdwall. In this way the effort required to completely wet a tablet willalso increase in the direction from the second wall to the third,ensuring that each upstream tablet has been properly wetted when wettinga more downstream tablet, thus providing very homogeneous wetting of thetotal volume of extractable product.

The invention further relates to a method for manufacturing the abovedescribed capsule, comprising:

providing a coffee receiving cup comprising the circumferential firstwall and one of the second and third walls defining an inner spacearranged for receiving roast and ground coffee;

providing an amount of roast and ground coffee in the inner space of thecoffee receiving cup having a preselected distribution by weight,wherein a 10th percentile of the particle size is 20-60 μm, preferablyless than 40 μm, wherein a 50th percentile of the particle size is400-600 μm, preferably 450-550 μm and wherein a 90th percentile of theparticle size is 700-1000 μm, preferably 825-950 μm.

It will be appreciated that the step of providing may comprise the stepof compressing an amount of roast and ground coffee starting materialsuch that the capsule comprises compacted coffee having the particledistribution as is set forth in claim 1. For example, particles of thecoffee starting material may have the following distribution by weight:a 10th percentile of the particle size may be 25-55 μm, preferably lessthan 40 μm, a 50th percentile of the particle size may be 450-550 μm anda 90th percentile of the particle size may be 600-800 μm.

The total amount of coffee may be provided in the inner space of thecapsule and subsequently be compressed to compact said amount of coffee.

In an alternative embodiment of the method of the invention, the methodmay comprise:

providing a first part of the amount of roast and ground coffee startingmaterial in the inner space;

compressing said first part such that the first part is compacted;

subsequently providing a further part of the amount of roast and groundcoffee starting material on top of the compressed first part in theinner space of the capsule;

compressing the further part such that the further part is compacted. Byalternately providing and compressing parts of the amount of coffee, thecoffee may be more easily inserted in the capsule and at the same timerisk of spoiling coffee starting material may be reduced.

It will be appreciated that the tablet or tablets may have thepre-determined particle size distribution as is described with referenceto claim 1. The coffee starting material may have particle distributionas is set forth in the foregoing.

It is also possible according to a further aspect of the invention, thatthe coffee starting material that is inserted in the inner space of thecapsule is condensed by means of vibration prior to compressing saidcoffee starting material.

Preferably, the compacted volume of the roast and ground coffee issubstantially similar to a volume of the inner space of the coffeereceiving cup.

Such a method provides the advantage that distribution of the coffeeparticles inside the coffee receiving cup of the exchangeable capsulecan be determined during the manufacturing process. The distribution ofthe coffee particles thus can be homogenous, wherein relatively smallparticles may be enclosed by relatively large particles. Due to thecompaction of the coffee, the distribution will not considerably changeduring for instance transport of the exchangeable capsules.Consequently, the predetermined distribution of the particles inside thecapsule may remain intact. By preparing a beverage with such a capsule,the coffee preparation process may be controllable and reproducible.

Furthermore, by compacting the coffee in the inner space of the capsule,a flat surface is provided at the side of the exchangeable capsule towhich the exit filter has to be connected. Such a flat surface enhancestight sealing of the exit filter onto the circumferential first wall ofthe exchangeable capsule, thereby preventing occurrence of aperturesbetween for instance the foil of the exit filter and the first wall. Thelatter may result in a capsule of inferior quality that may produce aninferior quality of beverage due to such apertures, coffee and fluid mayleak there through without passing the exit filter.

Compaction of the coffee further increases the sealing quality of theexit filter onto the circumferential first wall because the risk ofcoffee particles being located on the circumferential first wall surfaceis decreased. Thus, sealing quality of the exit filter along the entirecircumferential first wall may not be diminished due to particlesbetween the filter and the wall.

In a further elaboration of the method according to the invention, theroast and ground coffee is compressed with a compressive pressure ofsubstantially 50-300N, preferably 50-500N, preferably of substantially400-600N. Good results have been achieved with a compressive pressure ofabout 500N.

In order to provide the predetermined amount of roast and ground coffeestarting material in the inner space of the coffee receiving cup with avolume of approximately 10-14, ml, preferably of 11.5-12.5 ml, morepreferably of approximately 11.8 ml, it is preferable that a pouringvolume of the roast and ground coffee starting material (not yetcompacted) is preferably in the range of 600-680 ml per 250 grams ofcoffee starting material. With such a pouring volume, the roast andground coffee after compression may have a weight of 4.0-8 grams,preferably 4.9-5.7 grams, preferably of approximately 5.3 grams±0.2grams. It will be appreciated that the term starting material refers toa condition of the coffee before it is introduced into the capsule.

Applicant found that if an exchangeable capsule according to theinvention comprises coffee with a pouring volume of less than 600 ml per250 grams of coffee starting material, a prepared cup of coffee usingsaid capsule results in a watery cup of coffee without a nice foamlayer. It will be appreciated that the pouring volume in this aspectrelates to a condition of the coffee before the step of compacting inthe capsule. Furthermore, if the pouring volume is less than 600 ml per250 grams the coffee beverage may comprise a relatively large amount ofcoffee oil, which negatively influences the quality of the preparedbeverage. A high pouring volume, higher than the preferred volume asmentioned above, is also undesirable because it may result in a too longbeverage preparation time.

It is noted that the pouring volume of coffee starting material isdetermined by measuring the volume of 250 g of coffee after grindingpost densification. In order to determine this volume, an amount ofroast and ground coffee starting material is poured from a funnel into atray provided there under to that end, which tray has a volume of 250ml. The tray has a slide which is closed, so that the volume of coffeegrindings of 250 ml remains in the tray. Then, the weight of the coffeegrindings in the tray is determined and converted into a pouring volumeexpressed in ml/250 g.

Furthermore, it is desirable that according to a further aspect of theinvention, the roast and ground starting material has a moisture contentof 1.0-4.0%, preferably of 1.5-2.2%, more preferably of approximately1.5% before compacting the roast and ground starting material in theinner space of the capsule. The moisture content of the coffee startingmaterial is formed in that the coffee starting material is quenched withmoisture before the coffee starting material is ground. The moisturecontent is determined by measuring an extent of weight loss of 5 gcoffee starting material as a result of drying the coffee startingmaterial in an oven for 3 hours at 103° C.

Preferably, according to a further embodiment of the method according tothe invention, the coffee beans intended for the roast and ground coffeestarting material are roasted during approximately 250-1000 seconds,preferably during 450-700 seconds, wherein a degree of roast of theroast and ground coffee starting material preferably is in the range of30-60. An exchangeable capsule comprising such roast and ground coffeeprovides a cup of coffee beverage with a nice flavor comprising anacceptable amount of coffee oil. Such a degree of roast further providesroast and ground coffee starting material that can be compacted in adesired manner with a desired pressure as mentioned before. The degreeof roast of the coffee starting material is determined by measuring thereflection of light on a leveled amount of ground coffee startingmaterial. This can be carried out with, for instance, a color analyzerLK100, type LMG163 of Dr. Bruno Lange GmbH. An amount of light, forinstance of a wavelength of 640 nm, is directed at a sample comprisingsaid leveled amount of grindings. Depending on the darkness of thegrindings, an amount of light is reflected and measured. The valueindicates the degree of roast. Said color analyzer is calibrated dailyby subsequently using two calibration tiles. Thereafter said calibrationtiles are measured and then the sample is measured. If needed, theroasted beans are grind to a particle size fine ¾, having an averageparticle size of approximately 0.39 mm. Leveling off the coffee shouldbe done by keeping a ruler upright and making a 90 degree angle with thesurface of the coffee. The coffee is leveled off in three smoothmovements (to and fro) over the brim of the sample-dish. If obviousirregularities are determinable on the coffee surface, leveling shouldbe done again.

In further elaboration of the invention, the coffee beans are grinded toprovide roast and ground starting material with a particle sizedistribution by weight, wherein a 10th percentile of the particle sizeis 25-55 μm, wherein a 50th percentile of the particle size is 400-550μm, and wherein a 90th percentile of the particle size is 600-800 μm.When compressing such roast and ground starting material in the innerspace of the capsule, a predetermined homogenous distribution of theparticles can be provided as explained before having the particledistribution as is set forth in claim 1.

The invention also relates to a capsule obtainable by the abovedescribed method and to a system for preparing a predetermined quantityof beverage suitable for consumption according to claim 27 and to amethod for preparing a predetermined quantity of beverage suitable forconsumption according to claim 29.

Further advantageous embodiments of the capsule, the method formanufacturing such a capsule, the system and the method for preparing abeverage according to the invention are set forth in the dependentclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further elucidated by means of, non-limiting,examples referring to the drawing, in which

FIG. 1 shows an example of a first embodiment of a system for preparinga beverage according to the invention;

FIG. 2 shows a first embodiment of a capsule according to the invention;

FIG. 3 shows the capsule of FIG. 2 during preparation of a beverage;

FIG. 4 shows a second embodiment of a capsule according to theinvention;

FIG. 5 shows a third embodiment of a capsule according to the invention;and

FIG. 6 shows a fourth embodiment of a capsule according to theinvention;

It is noted that identical or corresponding elements in the differentdrawings are indicated with identical or corresponding referencenumerals.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIG. 1 shows an example of a first embodiment of a system 1 forpreparing a predetermined quantity of beverage suitable for consumptionusing an extractable product according to the invention. The system 1comprises an exchangeable open capsule 2, and an apparatus 4. Theapparatus 4 comprises a receptacle 6 for holding the exchangeablecapsule 2. In FIG. 1, a gap is drawn between the capsule 2 and thereceptacle 6 for clarity. It will be appreciated that, in use, thecapsule 2 may lie in contact with the receptacle 6. In this example thereceptacle 6 has a shape complementary to the shape of the capsule 2. Inthis example the receptacle 6 comprises an upper part 8 and a supportsurface 10.

The apparatus 4 further comprises a fluid dispensing device 12 forsupplying an amount of a fluid, such as hot water, under a highpressure, of e.g. more than approximately six bars (absolute pressure),to the exchangeable capsule 2.

In the system 1 shown in FIG. 1, the exchangeable capsule 2 comprises asubstantially rigid circumferential first wall 14, a second wall 16closing the circumferential first wall 14 at a first end 18, and a thirdwall 20 closing the circumferential first wall 14 at a second, open, end22 opposite the second wall 16. The circumferential first wall 14, thesecond wall 16 and the third wall 20 enclose an inner space 24comprising the extractable product, in this example roasted and groundcoffee. In this example, the exchangeable capsule 2 comprises an amountof extractable product, e.g. approximately 4.9-5.7 grams of roasted andground coffee, preferably of approximately 5.3 grams±0.2 grams, suitablefor preparing a single portion of the beverage, preferably a single cupof the beverage, e.g. from 30-200 ml of the prepared beverage.

In the capsule 2 according to the invention roast ground coffee isprovided whose particles are falling within a preselected distributionby weight, wherein a 10th percentile of the particle size is 20-60 μm,preferably less than 40 μm, wherein a 50th percentile of the particlesize is 400-600 μm, preferably 450-550 μm and wherein a 90th percentileof the particle size is 700-1000 μm, preferably 825-950 μm.

It is found that such particle distribution has advantageous effect ondecreasing the brew time and amount of sediment in the cup. However, itwill be appreciated that there is interplay between the followingparameters: grinding size, amount of coffee, amount and a dimension ofthe openings in the exit area of the third wall and the brew time andthe sediment accumulated in the cup.

For example, by increasing the grinding size brew time and amount of thesediment in the cup may be decreased to an advantage. It is found thatthe size distribution of the particles in the open capsule according tothe invention amount of coffee necessary for producing a tasteful coffeedrink may be decreased, which has an economic advantage.

Dependent on the desired strength of the prepared beverage the amount ofextractable product may vary. For instance for preparing a cup ofespresso coffee, the capsule 2 may comprise approximately 5.3 grams andfor preparing a cup of coffee longo, the capsule 2 may compriseapproximately 6.0 grams. In another embodiment of the invention, thecapsule may also comprise other amounts between 4.0-8 grams, preferablybetween 4.9-5.7 grams of coffee. The inner space 24 may have a volume ofapproximately 10-14 ml, preferably 11.5-12.5 ml, more preferablyapproximately 11.8 ml. The exchangeable capsule, thus, is asingle-portion-pack. According to a further aspect of the invention, theextractable product in the inner space 24 of the capsule 2 is compacted.

In the example of FIG. 1, the circumferential first wall 14 issubstantially rigid. The circumferential first wall 14 may e.g. comprisea plastics material and may be formed by e.g. injection molding,vacuum-forming, thermoforming or the like.

In this example the second wall 16 is integral with the circumferentialfirst wall 14. In this example the second wall 16 is substantially rigidand comprises a plurality of entrance openings 26 for allowing the fluidto enter the capsule 2. The second wall 16 provides an entrance filterof the capsule 2.

In this example the third wall 20 is flexible and sheet-shaped. Further,in this example the third wall is porous. The third wall 20 is in thisexample manufactured from filtering paper. In this example the filteringpaper comprises polyethylene (PE) fibers. In this example the third wall20 is connected to the circumferential first wall 14 by heat sealing. Inthis example the third wall 20 forms an outermost boundary of thecapsule 2 in an axial direction thereof. It can be seen from FIG. 1 thatthe third wall 20 abuts against the support surface 10 of the receptacle6.

The system 1 shown in FIG. 1 is operated as follows for preparing a cupof coffee.

The capsule 2 is placed in the receptacle 6. The third wall 20 isbrought into abutment with the support surface 10. The fluid, here hotwater under pressure, is supplied from the fluid dispensing device 12 tothe extractable product in the inner space 24 through the entranceopenings 26. The fluid dispensing device 12 may be adapted to supply thewater to the exchangeable capsule 2, under a pressure of approximately4-20 bars, for instance 9-15 bars, preferably about 6 bars. Good resultshave been obtained with the pressure of about 6 bars build-up in thefluid dispensing device. The water will wet the coffee grounds andextract the desired substances to form the coffee beverage. The preparedcoffee will drain from the capsule 2 through the porous third wall 20.The coffee beverage is further drained from the receptacle 6 via aplurality of outlets 28, and may be supplied to a container 30 such as acup. During the supply of the water to the compacted coffee in the innerspace of the capsule 2, coffee particles are redistributed in the innerspace 24 of the capsule 2, such that a relatively loose coffee bed layerL adjacent the second wall 16 and a relatively compact coffee bed layerC adjacent the third wall 20 is formed (see FIG. 3). The relativelysmall particles S are displaced together with the water towards the exitfilter forming third wall 20 and will be located adjacent openings 38 ofthe exit filter 20. Said small particles S will together with the exitfilter 36 form the flow restriction of the capsule 2 (see FIG. 3)providing a desired pressure drop and thus a desired extraction pressureinside the capsule 2, such that the soluble dry matter from thecompacted coffee can be extracted and a cup of beverage with a desiredbrewing strength and quality is obtained.

In the example of FIG. 1 the plurality of entrance openings 26 isdistributed over substantially the entire second wall 16. Thus, thefluid is supplied to the extractable product via the plurality ofentrance openings 26, which causes the extractable product to be wettedover substantially the entire cross section of the capsule 2. Hence, avery homogeneous supply of fluid to the extractable product is obtained.Thus, the risk of occurrence of preferential paths via which the fluidflows through the extractable product is greatly reduced.

In another (not shown) embodiment of the capsule 2 according to theinvention, the third wall 20, forming the exit filter of the capsule 2,through which the beverage, here coffee, can drain from the capsule 2,is formed by a porous sheet, such as filter paper. The entire third wall20 may then be formed as the porous sheet. For example, the third wall20 may form a substantially continuous fluid-permeable sheet spanningsubstantially the entire second open end 22 of the capsule 2. Thus, thefluid can drain from the capsule 2 over a large area. Hence, a veryhomogeneous drain of beverage from the extractable product is obtained.Thus, the risk of occurrence of preferential paths via which the fluidflows through the extractable product is greatly reduced.

It will be appreciated that in other not shown embodiments of thesystem, the apparatus may be different than the apparatus as describedin the first embodiment of the system. For instance, the apparatus canbe provided with a hollow space between the third wall 20 of the capsule2 and the outlet openings 28 of the apparatus 4. In another example, theapparatus may comprise piercing means for piercing a lid of ahermetically sealed known capsule. Thus it is noted that the capsuleaccording to the invention can be used in any suitable apparatus forpreparing a beverage by using high pressure.

FIGS. 2-5 show embodiments of capsules according to the invention. InFIG. 2 the second wall 16 is integral with the circumferential firstwall 14 like in FIG. 1. The second wall 16 comprises the plurality ofentrance openings 26 in the second wall 16. The third wall 20 is formedby a flexible foil 36, e.g. a polymeric foil, provided with a pluralityof exit openings 38. In FIG. 2 the capsule 2 comprises an outwardlyextending rim 40 at the second end 22 of the circumferential first wall14. The third wall 20 is attached to the outwardly extending rim 40,e.g. by means of gluing, welding, heat sealing, or the like. Hence, thethird wall 20 can be firmly attached to the rim 40. It will beappreciated that it is possible that the outwardly extending rim 40extends between the upper part 8 of the receptacle 6 and the supportsurface 10 of the receptacle 6, such that the rim 40 is clamped betweenthe upper part 8 and the support surface 10. Hence, the third wall 20 isclamped against the rim 40 in use, i.e. when the fluid pressure isapplied, thus reducing the risk of the third wall 20 separating from therim 40.

In FIG. 4 the third wall 20 is formed by the flexible porous sheet, suchas filter paper. In FIG. 4 the second wall 16 is also formed by aflexible porous sheet, such as filter paper. In this example the secondwall 16 is attached to an inwardly extending flange 42. In this example,the second wall 16 is attached to the inner side of the inwardlyextending flange 42.

It is appreciated that in other not shown embodiments, the third wall 20may be formed by a porous sheet such as filter paper or by a polymericfoil, provided with a plurality of exit openings 30, like in FIGS. 1 and2. It will be appreciated that the capsule 2 may comprise any secondwall 16 according to any one of the shown embodiments in combinationwith any third wall 20 according to any one of the shown embodiments.Preferably, the circumferential first wall 14 is substantially rigid.Hence, the capsule 2 will not be prone to deform by shipping and/orhandling, so that the capsule 2 will always fit in the receptacle 6. Inaddition, the circumferential first wall 14 is preferably resilient, sothat any possible deformation of the circumferential first wall 14 willbe reversed once the force causing the deformation is removed.Nevertheless, it is possible that the circumferential first wall 14 isformed by a flexible sheet, preferably integral with the second wall 16.Hence, substantially the entire capsule 2 may be manufactured of theflexible sheet, reducing the amount of material required for providingthe capsule 2.

In the examples the circumferential first wall 14 is substantiallycylindrical. It will be appreciated that the capsule according to theinvention is not limited to this shape. The circumferential first wall14 may e.g. be frustoconical, hemispherical, or polygonal, such ashexagonal, octagonal, etc.

The capsule 2 according to the invention is preferably manufactured byproviding a coffee receiving cup 32 comprising the circumferential firstwall 14 and the second wall 16. The first wall 14 and the second wall 16define the inner space 24. Roast and ground coffee starting material,for instance Arabica coffee with a maximum of 30% of Robusta coffee,with a desired particle distribution, a desired moisture content, adesired degree of roast and a desired pouring volume is supplied intothe inner space 24 of the coffee receiving cup 32. Then the coffeestarting material is compressed by a suitable compression means, forinstance with a compression force of approximately 500N. Aftercompression of the coffee in the inner space 24 of the cup, the surfaceof the compressed coffee facing away from the second wall 16 may besubstantially flat. Furthermore, at most a limited amount of coffeeparticles may be located on a top surface of the circumferential firstwall 14 facing away from the second wall 14. In this example of thecapsule 2 according to the invention, at most a limited amount of coffeeparticles, preferably no particles at all, may be located on theextending rim 40. Consequently, an exit filter, for instance a polymericfoil layer 36 can be easily provided and sealed in a tight manner ontothe extending rim 40 of the circumferential first wall 14 with aminimized risk of occurrence of unsealed areas between thecircumferential first wall 14 and the exit filter 20. This results in acapsule 2 having a substantially flat third wall 20, in other words, thethird wall 20 will not substantially extend from the circumferentialfirst wall 14 in a direction parallel to a central axis A of the capsule2 (see FIG. 3). Thus, when using such capsule 2 in an apparatus 4 forpreparing a beverage, the capsule 2 can be easily placed in thereceptacle 6 without getting stuck due to an extending third wall 20. Inan alternative embodiment of the invention it is possible that a firstpart of the coffee starting material is inserted into the inner space 24of the capsule 2. This first part of the coffee starting material may becompressed by a suitable compression means, for instance with acompression force of approximately 500N. It will be appreciated that thecompression means may rotate during compressions or in intervals betweensubsequent compressions. This has an advantage that oils maysubstantially decrease at one hand and that DMA's may increase or stayat the same level on the other hand. Subsequently, on top of thecompressed first part of the coffee starting material a further part ofthe amount of roast and ground coffee starting material (as is explainedin the foregoing) may be provided in the inner space 24 of the capsule2. Then the further part of the amount of coffee starting material iscompressed by a suitable compression means, for instance with acompression force of approximately 500N, such that the further part iscompacted. This provides an easy way of inserting and compressing thecoffee starting material in the capsule 2. It is also possible that themethod for manufacturing the capsule comprises alternately inserting andcompressing more than two parts of the amount of coffee startingmaterial inside the capsule 2.

FIG. 5 shows an example of the capsule 2 according to the invention,wherein the extractable product is compacted into a plurality of, inthis example four, tablets 58,60,62,64. In FIG. 5 the tablets58,60,62,64 are stacked inside the inner space 24. In FIG. 5, eachtablet 58,60,62,64 spans substantially the entire cross section of theinner space 24 of the capsule 2. In this example a density, i.e. adegree of compaction, of the tablets 58,60,62,64 is different for eachof the tablets. The density of the tablets 58,60,62,64 increases in thedirection from the second wall 16 to the third wall 20. This providesthe advantage that the fluid will more easily wet a tablet of lowerdensity than a tablet of higher density, so that each upstream tablethas been properly wetted while the water wets a subsequent downstreamtablet. Thus, highly homogeneous wetting of the extractable product isachieved. Although the example shows four stacked tablets, it will beappreciated that any number of tablets may be used.

FIG. 6 shows an example of a capsule 2 comprising a single tablet 66 ofcompacted extractable product. In the example of FIG. 6 the tablet 66comprises bores 68 extending into the tablet 66 from the side of thetablet 66 facing the second wall 16 in the direction of the third wall20. The length of the bores 68 is shorter than the thickness of thetablet 66 in the direction along the bore 68. Thus, the bores 68 do notform shortcut passages for the fluid through the tablet 66, but providethe fluid a passage into the core of the tablet 66. These bores 68 allowa predetermined penetration of the fluid into the tablet. Thus, apreferred wetting of the compacted extractable product may be obtained.

It will be appreciated that the tablet 66 or plurality of tablets58,60,62,64 may be used in conjunction with any capsule 2 referred tohereinabove. It will also be appreciated that if the extractable productis compacted into the tablet(s) the second wall 16 of the capsule is notstrictly required, since the extractable product is not likely to spillfrom the capsule 2 prior to use.

In the foregoing specification, the invention has been described withreference to specific examples of embodiments of the invention. It will,however, be evident that various modifications and changes may be madetherein without departing from the broader spirit and scope of theinvention as set forth in the appended claims.

It is for instance possible that the open capsule is contained in an airtight wrapping prior to use to improve shelf-life.

It is for instance possible that the capsule 2 is manufactured frombiodegradable materials.

It is for instance possible that the capsule 2 has different dimensionsor different shapes.

It further may be possible that the coffee is compacted in the innerside of the capsule by using different suitable apparatuses forcompacting

The coffee may, in an alternative embodiment of the invention, becompacted before being supplied to the inner space of the capsule. Forinstance, by first compressing the coffee starting material into atablet with dimensions corresponding with dimensions of an inner spaceof a coffee receiving cup of the capsule.

However, other modifications, variations and alternatives are alsopossible. The specifications, drawings and examples are, accordingly, tobe regarded in an illustrative rather than in a restrictive sense.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word ‘comprising’ does notexclude the presence of other features or steps then those listed in aclaim. Furthermore, the words ‘a’ and ‘an’ shall not be construed aslimited to ‘only one’, but instead are used to mean ‘at least one’, anddo not exclude a plurality. The mere fact that certain measures arerecited in mutually different claims does not indicate that acombination of these measures cannot be used to advantage.

1. A capsule for preparing a predetermined quantity of beverage suitablefor consumption using an extractable product, for instance roast andground coffee, the capsule comprising: a circumferential first wall, asecond wall closing the circumferential first wall at a first end, aperforated and/or porous third wall closing the circumferential firstwall at an open second end opposite the second wall arranged fordraining the prepared beverage from the capsule, wherein the first,second and third wall enclose an inner space comprising the extractableproduct, wherein the extractable product in the inner space hasparticles falling within a preselected distribution by weight, wherein a10th percentile of the particle size is 20-60 μm, preferably smallerthan 40 μm, wherein a 50th percentile of the particle size is 400-600μm, preferably 450-550 μm, and wherein a 90th percentile of the particlesize is 700-1000 μm, preferably 825-950 μm.
 2. The capsule according toclaim 1, wherein the extractable product of the capsule has been, atleast partly compacted.
 3. The capsule according to claim 1, wherein thecapsule comprises 4.0-8 grams, preferably 4.9-5.7 grams of roast andground coffee.
 4. The capsule according to claim 1, wherein the innerspace of the capsule has a volume of approximately 10-14 ml, preferably11.5-12.5 ml, more preferably approximately 11.8 ml.
 5. The capsuleaccording to claim 1, wherein the entire inner space is occupied by theextractable product.
 6. The capsule according to claim 2, wherein theroast and ground coffee is compacted such that the compacted coffee inthe inner space comprises a substantially homogenous density.
 7. Thecapsule according to claim 1, wherein the third wall comprises an exitfilter arranged for draining prepared beverage from the capsule, whereinthe exit filter for instance is formed by a woven or non-woven fibroussheet, such as filtering paper, or a polymeric film provided with aplurality of exit openings.
 8. The capsule according to claim 7, whereinthe exit filter comprises 80 140 exit openings, wherein an openingdiameter is between 0.4 mm±0.05 mm and 0.2 mm±0.05 mm, preferablyapproximately 0.3 mm±0.05 mm.
 9. The capsule according to claim 1,wherein the first circumferential wall is substantially rigid.
 10. Thecapsule according to at least claim 7, wherein the extractable productof the capsule has been, at least partly compacted, and wherein thecapsule comprises an entrance filter, wherein the entrance filter has aflow resistance that is lower than the flow resistance of the compactedextractable product in combination with the exit filter.
 11. The capsuleaccording to claim 1, wherein the compacted beverage ingredient isprovided in a tablet.
 12. The capsule according to claim 11, wherein thetablet comprises at least one bore extending from the side of the tabletfacing the second wall in the direction of the third wall.
 13. Thecapsule according to claim 11, wherein the extractable product iscompacted into a plurality of tablets, preferably of mutually differentpacking density.
 14. The capsule according claim 13, wherein acompaction density increases from the second wall of the capsule towardsthe third wall of the capsule.
 15. A method for manufacturing a capsulecomprising: providing a capsule having a circumferential first wall, asecond wall closing the circumferential first wall at a first end, aperforated and/or porous third wall closing the circumferential firstwall at an open second end opposite the second wall arranged fordraining the prepared beverage from the capsule, providing a coffeereceiving cup comprising the circumferential first wall and one of thesecond and third wall defining the inner space arranged foraccommodating roast and ground coffee which has particles falling withina preselected distribution by weight, wherein a 10th percentile of theparticle size is 20-60 μm, preferably smaller than 40 μm, wherein a 50thpercentile of the particle size is 400-600 μm, preferably 450-550 μm andwherein a 90th percentile of the particle size is 700-1000 μm,preferably 825-950 μm; providing an amount of said roast and groundcoffee in the inner space of the coffee receiving cup.
 16. The methodaccording to claim 15, wherein the step of providing comprises the stepof compacting the amount of roast and ground coffee starting materialsuch that the capsule comprises compacted coffee having the saidpreselected distribution by weight.
 17. The method according to claim15, wherein the method comprises: providing a first part of the amountof roast and ground coffee starting material in the inner space;compacting said first part such that the said first part is compacted;subsequently providing a further part of the amount of roast and groundcoffee starting material on top of the compacted first part in the innerspace of the capsule; compacting the further part.
 18. The methodaccording to claim 15, wherein a compacted volume of the roast andground coffee is substantially similar to a volume of the inner space ofthe coffee receiving cup.
 19. The method according to claim 16, whereinthe roast and ground coffee starting material is compressed with acompressive pressure of substantially 50-800N, preferably ofsubstantially 400-600N, more preferably about 500N.
 20. The methodaccording to claim 15, wherein the inner space of the capsule has avolume of approximately 10-14 ml, preferably 11.5-12.5 ml, morepreferably approximately 11.8 ml.
 21. The method according to claim 15,wherein the compacted roast and ground coffee has a weight of 4.0-8grams, preferably 4.9-5.7 grams.
 22. The method according to claim 15,wherein the roast and ground coffee starting material has a pouringvolume in the range of 600-680 ml per 250 grams of coffee before it isintroduced in the capsule.
 23. The method according to claim 15, whereinthe roast and ground coffee starting material has a moisture content of1.0-4.0%, preferably of 1.5-2.2%, more preferably of approximately 1.5%.24. The method according to claim 16, wherein coffee beans for the roastand ground coffee starting material are roasted during approximately250-1000 seconds, preferably during 450-700 seconds.
 25. The methodaccording to claim 15, wherein a degree of roast of the roast and groundcoffee starting material is in the range of 30-60.
 26. A capsuleobtainable by a method according to claim
 15. 27. A system for preparinga predetermined quantity of beverage suitable for consumption using anextractable product, the system comprising: an exchangeable capsulehaving a circumferential first wall, a second wall closing thecircumferential first wall at a first end, a perforated and/or porousthird wall closing the circumferential first wall at an open second endopposite the second wall arranged for draining the prepared beveragefrom the capsule; and an apparatus comprising: a fluid dispensing devicefor supplying an amount of fluid, such as water under a high pressure tothe exchangeable capsule, a receptacle for holding the exchangeablecapsule and an outlet which, in use is in fluid communication with thecapsule for draining the prepared beverage from the capsule andsupplying the beverage to a container such as a cup.
 28. The systemaccording to claim 27, wherein the fluid dispensing device is adapted tosupply fluid to the exchangeable capsule under a pressure ofapproximately 4-20 bars, preferably 9-15 bars.
 29. A method forpreparing a predetermined quantity of beverage suitable for consumptionusing an extractable product, for instance roast and ground coffee,comprising: providing an exchangeable capsule having a circumferentialfirst wall, a second wall closing the circumferential first wall at afirst end, a perforated and/or porous third wall closing thecircumferential first wall at an open second end opposite the secondwall arranged for draining the prepared beverage from the capsule;providing an apparatus comprising a receptacle for holding theexchangeable capsule, a fluid dispensing device for supplying an amountof fluid, such as water, under a pressure of at least six bars to theexchangeable capsule, and an outlet which, in use is in fluidcommunication with the capsule for draining the prepared beverage formthe capsule and supplying the beverage to a container such as a cup;arranging the exchangeable capsule in the receptacle; supplying thefluid under pressure to the compacted extractable product for preparingthe beverage thereby redistributing relatively small coffee particles inthe inner space of the capsule such that said coffee particles arelocated adjacent the exit filter and together with the exit filterprovide a flow restriction of the capsule.
 30. The method according toclaim 29, further comprising: using a system comprising: a fluiddispensing device for supplying an amount of fluid, such as water undera high pressure to the exchangeable capsule, a receptacle for holdingthe exchangeable capsule, and an outlet which, in use is in fluidcommunication with the capsule for draining the prepared beverage fromthe capsule and supplying the beverage to a container such as a cup.